Furnace.



Patented May 30,1916.

3 SHEETS-SHEET I.

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FURNACE.

PPLICATION FILED DEC. 1. 1911.

v w T W/zmrcs- 33 Patentd May30, 1916.

3 SHEETS-SHEET 2.

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J. W. BROWN.

FURNACE.

APPLICATION FILED DEC. I, 1911- Patented May 30,1916.

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UNITED STATES PATENT OFFICE.

JOHN W.

BROWN, 0! LAKEWOOD, OHIO, ASSIGNOB TO THE NATIONAL CARBON COI- PANY, OICLEVELAND, OHIO, A CORPORATION OF NEW JERSEY.

FURNACE.

Specification of Letter! Patent. 1

To all whom it may concern:

Be it known that I, JOHN W. BRowN, a citizen of the United States,residing at Lakewood, in the county of Cuyahoga and State of Ohio, haveinvented a certain new and useful Improvement in Furnaces, of which thefollowing is a full, clear, and exact description.

This invention relates to a furnace for the heating of finely dividedmaterial which is a conductor of electricity. 1

The object of the invention is to construct a furnace in which theelectrical energy is transformed into heat energy within the body ofmaterial being heated, and brings that portion of the charge undertreatment to its maximum temperature, in a short space of time, andfurther secures a uniform treatment of the material.

Generally speaking, the invention includes the elements and combinationsthereof set forth in the accompanying claims.

Reference should be had to the accompanying drawings forming a part ofthis specification in which- Figure 1 is a central vertical section ofone form of furnace; Fig. 2 is a vertical section of another form offurnace; Fig. 3 is a vertical sectionof another form of furnace; Fig. 4is a figure of still another form of furnace; and Fig. 5 is a centralvertical section of another form of furnace.

While the furnace disclosed is capable of treating any material whichmay form a conductor for the electric current, it is more especiallyintended for the treatment of granular or finely divided carbon. Inheating this substance, in the forms of furnaces which have heretoforebeen proposed, it is difiicult to heat the charge with uniformity, andwhere such is not done, the resultant material after treatment must besubsequently dealt with to separate the carbon which has not beensufficiently treated for the purpose.

In the form of furnace here proposed, the material is fed into theheating zone of the furnace in such manner that the top may assume aslanting or conical form and the electric current is caused to passbetween the top of the cone and the base thereof. This insures acomplete heating of the material, and inasmuch as the quantity ofmaterial within the heating'zone at a given time is not great, thismaterial will be brought to the desired temperature in a short space oftime, and also, because of the small quantity under treatment at a giventime, the entire quantity of material thus Patented May 30, 1916.

sage of the current may be subjected to this heat during any period oftime which may be1 necessary to accomplish the desired resu 1:.

Referring to the forms of furnace shown in Fig. 1, the same comprisesouter walls 1,

which are preferably made of refractory material that is a non-conductorof electricity, these walls-being joined to or built upon a base 2. Atthe upper portion of the wall there is a cover 3, which incloses the.

space within the walls. Within the walls 1 are other walls 4, preferablymade of car-' bon, which extend from the base of the furnace up to apoint below the cover. Supported by the walls 4 and 1 is an inside coveror floor 5, which incloses the'space between the walls 1 and 4. Thisspace is filled with granular carbon forming'a layer of heat insulatingmaterial. In the case of the furnace there is formed a trough in whichis placed a conveyer 6 of any desired type. This conveyer in operationremoves material from the heating chamber and'conveys it to the outsideof the furnace. Extending through the chamber above the conveyer arepipes 7 through which passes a cooling medium, the same acting tocoolthe charge of material before the same is removed fromthe heatingchamber. Extending through the cover 3 is a hollow electrode 8 whichprojects well into the chamber inclosed by thewalls'. The material to betreated is fed through the electrode 8, and for this purpose there isprovided a funnel shaped member 9 upon the top of the electrode 8.

The bus bar 10 is electrically connected with the electrode 8, andserves as a means for the introduction of the electric'current. Abovethe cover 3 there is a cooling jacket 11, which is hollow and has pipes12 and 13, communicating therewith, for the circulation of water throughthe jacket. Extending through the walls 1 and l are electrodes l-l and15, the same intersecting the chamber within the walls 2 at a point justbelow the termination of the electrode 8. When the material is fedthrough the hollow electrode 8, and passes out at the lower end thereof,it' immediately spreads out to fill the heating chamber formed withinthe walls I. and the surface of the material as it is thus fed. assumesa slanting or conical form, as indicated at 17 in Fig. 1. The electrodesll and 15 are so placed that they are substantially at the base of theconical portion assumed by the material in passing from the electrode 8.It will therefore be clear that the path of the electric current liesbetween the top and bottom of the conical portion of the charge, andtherefore every particle of the material as it issues from the electrodeis subjected to the heat produced by the resistance of the material, asthe current passes through the same. As before stated. the materialbeing treated is removed from the heating chamber at the lower portionthereof by the conveyer 6. This conveyer may be operated at any desiredspeed. and therefore it is possible to subject the material undertreatment by the electric current to any desired extent or duration oftreatment. It should be noted that the material in passing through thehollow electrode 8 is preliminarily heated by the heat radiatingupwardly through the material from the heating chamber. The space.inclosed by the walls 4: and the covers 3 and 5 above the top of thematerial within the heating chamber forms a condensing chamber for thegases and vapors arising from the charge as the same is treated. Thesevapors when condensed may be removed from the chamber by means of theoutlet 16. An opening 16 is also provided through which the uncondensedvapors and gases may be removed. thereby preventing an undue pressure onthe condensing chamber arising from the accumulated gases. In the formof furnace shown, the electrodes may be so electrically connected that asingle phase current, or a polyphase current may be used.

In Fig. 2 the outer inclosing walls are indicated at 1 which walls restupon the base 2", and a cover 3 rests upon the top of the walls 1. Thewalls, base and cover are usually made of refractory material. Withinthe walls 1 are other walls 4 preferably of carbon which extend from thebase 2* to a point below the cover 3. or cover 5 resting upon the walls4 and also supported by the walls 1. A partition o divides the heatingchamber inclosed by the walls 4., this partition being substantiallycoextensive with the walls 4. \Vithin the base 2 at the lower portion,troughs are formed, each of which forms the lower portion of one of theheating chambers inclosed within the walls 4". \Vithin each of thetroughs are conveyers (3" which may assume any desired form, and in eachof the heating chambers above the conveyers are cooling pipes 7, throughwhich may pass any suitable cooling medium. Extending through the cover3 are electrodes 8" and 8. These electrodes extend into the heatingchambers formed by the walls 4 and. partitions 5 and are hollow.Extending through the walls 1 and 4 are electrodes 14 and 15, theseelectrodes intersecting the wall l at a point which is just below thetermination of the electrodes 8 and 8*. The electrodes 8 and 8 arecooled by water jackets, one of which is shown at 11*, in the samemanner as has heretofore been explained. The materialto be treated isfed through the electrodes 8 and 8 in any suitable manner, and inpassing from the lower end of the electrodes, fills the heating chamher; the top of the charge of the material as it passes from the hollowelectrodes, assuming a slanting or conical form, as indicated at 17. Thespace above the charge of material inclosed by the walls I and by thecover 3 forms a condensing chamber for the gases and vapors as thematerial is heated, and the openings 16 are provided for the removal ofthe condensed gases and vapors, while, through openings 16" theuncondensed gases and vapors may be removed. The space between the walls.l and 1 and below the floor or cover 5 is filled with granular carbonto form a heat insulating body. The electrodes 8, S ll and 15 may besuitably connected with sources of electricity and the electric currentemployed may be either a single phase, a polyphase or a direct current.The manipulation of the material charged within the furnace issubstantially the same as that which has heretofore been described.

In the form of the furnace shown in Fig. 3 the outer walls arerepresented at 1 and the inner walls at 4'. The middle partition isdesignated at 5" and extends to a height less than the height of thewalls 4". The electrodes are represented at 8 and 8 .the current beingintroduced and led out from the heating chambers through these twoelectrodes. As stated with regard to the fur-. naces heretoforedescribed, the inner wall members 4* and partition member 5" are ofcarbon. The space between the inner wall There is a floor 4" and theouter wall 1 maybe packed with anular carbon as shown in connection with*ig. 2, and with the exceptions above noted the furnace is the same asthat shown and described in connection with Fig. 2.

In Fig. 4 the outer walls of the furnace are represented at 1,thesebeing supported upon the base 2, and the furnace is provided with acover 3 which rests upon the top of the walls 1. Within the outer walls1 are inner carbon walls 4 which are spaced from the outer walls,-thisspace being filled with granular carbon to provide a heat insulatinglayer. The space between the walls 4 and 1 is inclosed at the topthereof by the floor or cover 5. In the lower part of the heatingchamber a conveyer 6 is provided by which material is removed from thelower part of the heating chamber, and in consequence of which removalthe material may flow or move through the chamber, thus making thefurnace a continuously operating one. Above the conveyer 6 are pipes 7through which a cooling medium maybe circulated for the purpose ofcool-,

ing the material being treated, before it is removed to the outside air.The electrode 8 is preferably circular and forms, in effect, a floorwith a central opening 9, through which material enters the heatingchamber. The opening 9 upon the underside of the electrode is providedwith a flange, this being for the purpose of guiding the materialcharged into the furnace, that it may assume the desired form, uponentering the heating chamber. The electrode 8 may be a circularelectrode, or two oppositely disposed electrodes joined by a bus bar maybe employed. The material to be treated is fed into the top of thefurnace, and for this purpose there is provided the hopper shaped memberindicated in the drawing. The space below the electrodes 8 and above thefloor or cover 5 provides a condensing chamber in which the gases andvapors arising from the charge being treated may be condensed and thesecondensed vapors are withdrawn from the furnace by means of the outlets16. It will be observed that the material to be heated must enter theheatingchamber through the opening 9 in the electrodes 8, thus enteringthrough an opening of less diameter than that of the heatlng chamber,and as the material enters the heating chamber the top surface thereofwill assume the slanting orconical form, the surface of which isrepresented at 16. It will be noted that the lower portions of thisslanting surface meets with the electrodes 8 and therefore the electriccurrent passing between the electrodes 8 and 8 will pass through thematerial comprehended within the slanting surface 16.

In Fig. 5 the side walls are represented at 1', the base at 2 and thecover at 3,

these being substantially the sameas shown in Fig. 4. Within the walls 1are the inner walls 4 which extend from the base to a point below thecover 3. through these walls and the outer walls as well are theelectrodes 8. Above the walls 4 is a partition or floor 9, which, inshape, is the same as that of the cross section of the furnace. Thisfloor 9? is formed with a central opening having a surrounding flangeupon the underside. The material enters the heating chamber through thisopening and upon entering the chamber, assumes the desired formheretofore explained. An eh ctrode 8 extends through an opening in thecover 3 to a point just within the walls of the heating chamber, so thatthe material entering the heating chamber flows around -the electrode 8,and the path of the electric current .between the electrodes 8 and 8 issuch as to heat the material comprehended within the slanting surface16It will be Extending understood that the material, as it is fed a intothe furnace through the hopper shown above the cover 3 will completelysurround the electrode and thus form a closure for the space between theopening in the cover 3 and the electrode 8. moved from the bottom of theheating chamber by a conveyer 6 in a manner similar to that previouslydisclosed, and, in fact, with the exception of the differences noted,this furnace is substantially the same as those which have heretoforebeen disclosed.

In all the furnaces which have been described, the heating efi'ect isapplied to the material as it enters the heating chamber, and at thistime is caused to assume a form which permits the electric current tocome into intimate contact with thevarious particles, and thus, by thetransformation of the electric current into heat energy, all theportions of that part of the charge being treated are subjected to theheat which is developed by the current. The quantity of material whichis treated in a given period of time is small, and by using a suitablequantity of electrical energy, it is possible to heat the material whichis subjected to the electric current in a very short time, and to giveit the required amount of treatment in a very short time. It is truethat the charge is continually descending The material is re I insubstantially uniform time, for if they do not, and some particles aredelayed, those particles or portions of the charge which are delayedwill become heated to a higher temperature than the remaining parts ofthe charge, and hence the electric current will, to a greater extent,flow through those portions which are heated, than through thoseportions of the charge which are not so highly heated. This, then, willresult in an unequal heating or treatment of the material, as it passesthrough the heating zone, and results in a non-uniform product.

The material passing through the upper part ofthe heating chamber orthrough the zone wherein the material is heated passes therethrough withsubstantially uniform movement, and therefore, from the fact that theelectric current flows between the top and the base of that portion ofthe charge of material having the slanting sides, it has been found thatall the material comprehended, in a given period of time, between theslanting sides will be thoroughly subjected to the heating action of thecurrent.

Having described my invention, I claim:

1. In a furnace, a heating chamber therein, means for introducingmaterial into said chamber in substantially conical form, and means forintroducing an electric current to flow substantially between the topand bottom of the conical portion of the charge.

2. In a furnace, a heating chamber therein, means for introducingmaterial into said chamber through an opening which is of less crosssectional area than the cross sectional area of the heating chamberwhereby the material assumes a slanting top surface, and means forintroducing an electric current to flow substantially between the topand bottom of the material comprehended by the slanting surface.

3. In a furnace provided with outer walls, inner walls within said outerwalls, said inner walls inclosing a heating chamber, means for feedingmaterial into said heating chamber through an opening of less crosssectional area than the cross sectional area of the heating chamberwhereby the material introduced into the furnace has slanting top sides,means for introducing an electric current to flow substantially betweenthe top and bottom of the material included within the slanting sides, aconveyer situated at the lower part of the heating chamber whereby thematerial may be removed therefrom.

4. In a furnace having an exterior wall{ interior walls within theexterior walls an spaced therefrom, granular carbon filling the spacebetween the interior and exterior terior walls inclosing a heatingchamber wherein material introduced therein may be heated, and means forheating the mateiial within the heating chamber.

6. In a furnace having exterior walls, i11

.terior walls within the exterior walls and spaced therefrom, saidinterior walls being formed of carbon, granular carbon materia fillingthe space between the interior walls and the exterior walls, and meansfor heating the material within the interior walls.

7. In a furnace, a heating chamber therein, a tubular feeding memberextending from the outside of the furnace into the heating chamber, thesaid tubular member being of less cross sectional area than the crosssectional area of the heating chamber whereby the material assumes acone-shape after passing through the tubular member, means for heatingthe material in the apex of said cone. 7

8. In a furnace, a plurality of heating chambers, a plurality of hollowelectrodes extending into said heating chambers whereby the material tobe treated may be introduced therethrough and a conducting partitionbetween said chambers whereby the electric current is caused to passthrough the hollow electrodes and the said )artition.

9. In a furnace, a plurality o heating chambers therein, said chambersbeing separated by a conducting partition, hollow electrodes extendinginto said chambers whereby the material may be introduced into thechambers through the said electrodes, means for causing the material tomove through the said chambers.

In testimony whereof, I hereunto afiix my signature in the presence oftwo witnesses.

JOHN W. BROWN. Witnesses:

F. D. LAURENCE, RICHARD A. HANEY.

